Data storage and retrieval systems are used to store information provided by one or more host computer systems. Such data storage and retrieval systems receive requests to write information to one or more secondary storage devices, and requests to retrieve information from those one or more secondary storage devices. Upon receipt of a write request, the system stores information received from a host computer in a data cache. In certain implementations, a copy of that information is also stored in a nonvolatile storage device. Upon receipt of a read request, the system recalls information from the one or more secondary storage devices and moves that information to the data cache. Thus, the system is continuously moving information to and from storage devices, and to and from the data cache.
One or more controllers coordinate receipt of information from one or more host computers, and the movement of information to and from the data cache and storage devices. What is needed is an apparatus and method to selectively provide power to one or more of those components disposed in the one or more controllers. In certain embodiments, Applicants' apparatus and invention are capable of selectively resetting one or more of components disposed in the one or more controllers.